Web marking device for xerographic reproducing apparatus



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M IL ES DAVIS A T TOI'PNE YS M. DAVIS WEB MARKING DEVICE FOR XEROGRAPHICREPRODUCING 'APPARATUS Filed Oct. 50, 1964 M. DAVIS April 5, 1966 WEBMARKING DEVICE FOR XEROGRAPHIC REPRODUCING' APPARATUS 2 Sheets-Sheet 2Filed Oct. 30, 1964 m. .bfi

-EN J.: /Tmt INVENTOR. MILES DAVIS BY ATTORNEYS United States Patent O3,244,084 WEB MARKING DEVICE FOR XEROGRAPHIC REPRODUCING APPARATUS MilesDavis, Rochester, N.Y., assigner to Xerox Corporation, Rochester, N.Y.,a corporation of New York Filed Oct. 30, 1964, Ser. No. 407,697 1 Claim.(Cl. 95-1.7)

This invention relates to improvements in xerographic reproductionapparatus and, particularly, to an improved device for marking andcutting a web type of surface on which xerographic reproductions areformed. More specifically, this invention relates to improvements inxerographicreproduction apparatus by which a support surface web onwhich xerographic reproductions are to appear may be marked for cuttingin spaced relation to the leading and trailing edges of the reproductioncorresponding to the leading and trailing edges of the originaldocuments being reproduced.

It is the practice on automatic xerographic printers, such as the typedisclosed in Patent No. 3,049,968, entitled, Xerographic ReproducingApparatus, to operate a continuously moving paper web support surfacefrom a supply roll to a takeup roll in between which xerographicreproductions are printed thereon. Since the original document, fromwhich the reproduction is formed, may vary in dimension and can bereproduced by the xerographic apparatus in magnified relation, a widevariance of spacing between successive prints may be required. Inaddition, it is the usual practice to move the paper web at a constantrate of speed, say, for example, approximately feet per minute (4 inchesper second) and, in so doing this, a continued absence of reproductioncauses a sizable accumulation of scrap paper on the takeup roll. Forexample, one minutes hesitation on the part of a human operator betweenfeeding successive originals to the apparatus effects approximately 20feet of scrap paper. On the other hand, accurately timed successivefeeding of originals for lll/z-inch reproductions results inapproximately 20 xerographically printed reproductions in the same weblength.

Heretofore, lthe usual practice has been to periodically remove thetakeup roll with the paper web wound thereon to another location whcreatthe paper was unwound and, with a manually operative cutter, cut the webso as to effect an approximate border on the leading and trailing edgeof each xerographic print. By these former cutting means, considerabledelay was incurred in effecting availability of the xerographicreproduction and, furthermore, required the services of additionalpersonnel employed for this specific function.

Because of the variable occurrence of the cut on the moving web, it ispreferable that a cutter mechanism be responsive to a reference means onthe web. ln order for the cutter to respond in spaced relation to thereproduction, the reference means should emanate from relation of theoriginal document to be reproduced whereby this relation is carriedforth to the reproduction on the support surface. When, as here, it isintended to cut the web in relation to both the leading and trailingedge of reproduction, the reference means should be assocated with itsrespective edge in order that the cutter be made to respond accordingly,that is, to cut the web in advance of a leading edge and after atrailing edge.

The principal object of this invention is to improve xerographicreproduction apparatus for marking and cutting a web type of surface onwhich xerographic reproductions are formed.

It is a further object of the invention to form electrostatic latentimage control patterns on a xerographic plate in relation toelectrostatic latent images corresponding to the positioning of originaldocuments to be reproduced.

These and other objects of the invention are attained by the apparatusherein disclosed and will be apparent from the following description.

A preferred form of the invention is shown in the appended drawings inwhich:

FIG. 1 is a schematic side elevation of an automatic xerographic printeremploying the apparatus of the invention;

FIG. 2 is a view illustrating the marker apparatus of the invention inrelation to the xerographic drum; and

FIG. 3 is a schematic diagram of the control circuit for the presentinvention.

Referring to FIG. 1, the paper web cutter assembly of the invention,generally designated as 10, shown in operative relation to a xerographicunit, generally designated as 12, which includes a xerographic plate inthe forrn of drum 14 mounted in suitable bearings in the frame of themachine, and is rotated at constant rate by motor 16. The drum comprisesa photoconductive surface 18 on a conductive backing that is sensitizedprior to exposure by means of a screened corona charging device 20,which may be of the type disclosed in Walkup Patent 2,777,957, that isenergized from a suitable high potential source.

Exposure of the drum to the light image emanating from an originaldocument discharges the photoconductive layer in the areas struck bylight, whereby there remains on the drum an electrostatic latent imagecorrespending to the light image projected. To project an opaqueoriginal onto surface 18, a scanningy apparatus 22 is employed which maybe of a type disclosed in Patent No. 3,105,425, granted to Cerasani etal. An original to be reproduced is manually fed from a support tray 24onto endless belts 26 which are continually moved at constant rateproportional to the rate or movement of the paper web 28 by a drivemotor 30.

As an original document moves on the belts, it passes under a sightglass 32 whereat an optical path is established from which the image onthe document is reflected from mirror 34, thence through an objectivelens 36 to a mirror 38 through a variable width exposure slit 40 so asto be exposed normal to the xerographic surface 13. A lamp 42 serves toilluminate the original document under the glass 32 and also serves toemit light to a copy detection device 44 when there is a spacing betweendocuments and in the absence of documents to be reproduced.

kAfter exposure, the image is developed by developing apparatus 46,which may be of the type disclosed in the above referred to Patent No.3,105,425, in which a twocomponent developer material is cascaded overthe drum surface 18.

` The support surface in the form of the paper web 28 is obtained from asupply spool 48, is fed over suitable guide and tensioning rolls anddirected into surface contact with the drum in the immediate vicinity ofcorona generating transfer device 50. After transfer, the supportsurface is separated from the drum surface and guided through a suitableheat fuser S2, which may be of a type disclosed in Crumrine et al.Patent No. 2,852,651, whereby the powder image is permanently affixed tothe support surface. Subsequent to the transfer of the image, anyresidual image on surface 18 is removed by fbrush cleaning with brushes54 which are rotated by motor 56. The web 2.8 then proceeds through webcutter assembly 10, as described below.

In order to detect the reference leading and trailing edges of theoriginal documents for effecting an electrostatic latent image controlpattern on surface 18 therefrom, the detection device 44 has a photocell60 which is adapted to receive light rays from the lamp 42 by reflectionfrom an inclined mirror surface 62. Light thereby transmitted isreceived by the light-sensitive photocell 60 which is characterized byemitting an electrical signal on the realization of light, wherein themagnitude of the signal varies in accordance with the intensity ofillumination realized. In' the preferred arrangement, the signal emitteddecreases in order of magnitude when there is an obstruction in theillumination path, such as the presence of documents on the belts 26,and increases in order of magnitude when no obstruction exists. As anoriginal document moves on .belts 26, the leading edge thereof effectsan obstruction of `the illumination path causing cell 60 to emit a lowlevel signal output and, when the document trailing edge moves out ofthe path, the signal produced by the photocell is of a higher level.

An electrostatic latent image control pattern is formed on one end ofthe drum surface 18, axially spaced from the adjacent edge of thedocument image. To produce the pattern, almarking device in the form ofa corotron 64 is operated by the detection of the detection device 44.The coro-tron 64, as shown in FIG. 2, includes a cylindrical shield 66closed at its upper end by an insulation disc 68 which supports acorotron electrode 70 at the center thereof. The lower end of the shield66y is bent inwardly to form an opening '72 through which coronadischarge, caused by the presence of a high electrical potential on theelectrode 70, will be directed upon the drum surface 18. Preferably, theopening 72 is square-shaped in order 4to produce a square-shaped,charged control image on the surface 18. The electrode, which is in theshape of a rod having a pointed discharge end, is positioned along theaxis of the opening 72 and spaced therefrom to produce an imageapproximately twice the size of the square opening 72. As shown in FIG.l, the corotron 64 is positioned a short distance from the exposure slit40 in the direction of rotation of the drum in order to permitenergization of the corotron immediately after the adjacent portions ofthe surface 18 have been discharged by exposure to the light images of adocument being scanned.

By the marker apparatus thus described, electrostatic latent imagecontrol patterns are formed on a xerographic plate which subsequentlyare developed and transferred to the support surface 28 and translatedtherefrom as a signal to effect subsequent cutter operation. Whereas thesignal produced is described herein with particular reference to effectoperation of a cutter apparatus, it is apparent that the markerapparatus could be employed to effect marking signals for otherpurposes, as, for example, to fold, punch, or other related operationsin reference to a point on the web, or xerographic reproduction.Furthermore, although particular emphasis is placed on effecting controlpatterns in a particular relationship with the leading and trailingedges of xerographic reproductions, variations in apparatus arrangementVwould perm-it effecting control patterns in any relation thereto.

- The web 18 is continuously drawn from the supply roll 4d and advancedthrough the paper cutter assembly It) by the motive force furnished froma motor '76. The force therefrom is transmitted through a suitable speedreducer and drive system, not shown, to drive a platen roller '78 underwhich the web 28 is in contact. rlhe web passes ,between two rollers 80as it is driven by the roller 7-8. Further description of the web drivemechanism, which is described in detail in Patent No. 3,105,425, is notnecessary for understanding of the present invention.

As the web passes Ibelow a detector means 82, the area thereof, on whichthe developed pattern marks corresponding to the latent control imagesproduced by the corotron 64 for the leading and trailing edges of adocument appear, is illuminated by a suitable lamp. As the pattern mark,corresponding to the leading edge of a document, passes into view underthe detector means 82, it is projected through a lens system S6 and intoa photocell 8S which immediately emits a `change in electrical signalinduced through the electric circuit means shown in FIG. 3. At thedetection of the pattern mark passing out from under the detection means82, another change in electrical signal is emitted by the photocell S8constituting a trailing edge signal.

As the web 28 passes the detector means 82, 4it moves between a knifemember 90, normally in an ineffective position, and a bed plate 92 ofthe knife or cutter assembly, generally designated as 10. A pair ofsolenoids 96 mounted on the assembly 10 have their plungers connected tothe knife member for actuating the same when energized for cutting Atheweb 28. After cutting, when the solenoids are deenergized, the knifemember is raised out of operative condition by a suitable spring, notshown.

`In operation, all the components of the xerographic unit 12 are intheir operating condition. The corona generating device 20 iscontinually applying a uniform electrostatic charge lon the surface 18and, in the absence of an original document, the corotron 64 isdeenergized due to unobstruction of the light rays from lamp 42 to thephotocell 60. The developing apparatus 46 is continually cascadingdeveloping powder over the'surface le and the web 28 is continuouslymoved between corona generating device Sti and the surface 18, throughthe fuser 52 and through cutter assembly 10, as aforesaid.

Referring to FIG. 3, positive rectified direct current is obtained fromthe part of the circuit generally outlined as itl@ and negativerectified direct current is obtained from the part of the circuitgenerally designated as T162. Switches S-ll, S-Z, and S-S aremechanically coupled to be actuated in unison and may be set to coincideat any of a number of optional positions of control. For discussionpurposes, it is assumed that all of the switches have been set to effectcutting of the web 28 on the leading and trailing edges of a Xerographicreproduction.

Referring to FlGS. l and 3, documents to be reproduced are first fedfrom support tray 24 onto moving belts 26. As a document is movedthereon, the leading edge of the document traverses the light rays fromthe lamp 42 and, in eifect, obstructs the illumination pat-h between thelamp and the pihotocell 60. This decrease Iin illumination, in effect,`decreases the electrical sign-al reaching pentode V-S 4and activatesthis tube to a bias below cut-off so as to deenergive Ia relay ICR.Tihis has the effect of opening the switch lCR-l thereby ideenergizingrelay 2CR and permitting normally closed switch ZCR-l to cause theenergization of the corotron 64.

After exposure of the document by means of the lens system 34, 36, 33,at the instant the trailing edge of the document has passed ove-r theglass plate 32 so as to readmit light from the lamp 42 to cell 60, thereis an increase in the signal emitted by pihotocell 60 Whichactivates thegrid of pentode V-S above cut-off, thereby energizing relay lCR andconsequently the relay ZCR -so as to effect opening of normally closedswitch ZCR-l. Opening of the switch ZCR-ll causes dee-ner-gization ofthe corotron 64.

While the corotron is energized, a peripheral charged latent line imageis formed on the surface 18 adjacent the edge of the latent image of thedocument. As succeeding documents are fed onto the belts 26, eachleading edge obstructs the illumination path from lamp 42 to photocell60 and again efects the energization of the corotron 64 to produce alatent image control pattern for each of the documents. The alternatingenergization of the corotron 64 eiiects an electrostatic latent ima-gecontrol pattern commencing and terminating in spaced relation on surface1S corresponding in length between the leading and trailing edge,respectively, of successive original documents., The-latent images ofthe documents and the latent image control patterns are thenxerographically developed, transferred and lixed in `the same spacedrelation on the, support web 2S, as previously stateid The surface are-aon web 28 occupied by the Xerographic control pattern mark may becontinually illuminated by suitable lamps, not show-n, and, at thedetection of the beginning of a pattern mark or the detection of itstermination, .as sensed by detector means 82, a change in electricalsignal is emitted by the photocell 88. On detection of the pattern mark,which causes a decrease in illumination to the photocell 88, the changeof signal emitted decreases and corresponds to the leading edge signalwhereas on detection of the termination of the mark there is a-nincrease in illumination at photocell 88, and the signal emittedincreases to correspon-d rto the trailing edge of the document.

On detection of a leading edge signal, the decrease 4in the signalproduced by the photocell 88 is transmitted through amplier circuit 164and differentiating circuit 106 and through a triode V-7B to energizerelay ECR through nonrnally closed switches 1LS-2 and 4CR-2 and thereby.close switches SCR-1 .and SCR-2. Closing of the switch SCR-1 forms aholding circuit through a triode V-8B, and the closing of the switchSCR-2 ener-gizes the timing clutch 110 of a timer 112 through a normallyclosed switch 1TR-1 to start a ytiming cycle. When the timer 112,Ihaving a preset time delay, times out, it causes energization of arelay 4CR .and the solenoids 96, closing of the switches 1TR-2 and1TR-3, and opening of the switch 4CR-2. Energization of the solenoids 96causes descending of the knife 90 to cnt web 28 in spaced relation to aleading edge of a Xerographic reproduction. As the cutter completes itsdownward stroke, some part thereof engages microswitches ILS-1 and ILSeZthereby opening their normally closed contacts. Since the relay 4CR ,andthe solenoids are energized by 'timer 112, the contact switches of 4CR-2are opened as the knife 90 completes its downward stroke and the holdingcircuit of relay 3CR is opened by the opening of the ILS-2 Whichdeenergizes the clutch 110. This action restores the timer 112 to itsoriginal condition, deenergizes the solenoids and releases the relay4CR. As the solenoids 96 are deenergized, suitable springs (not shown)actuate the knife 90 to its upper ineffective position.

On detection of a trailing edge signal which occurs at the end of thepattern mark, a signal from the photoccll 88 is applied to the Igrid ofa triode V-7A and thereafter is transmitted through the amplifiercircuit 104 and the differentiating circuit 116 to effect energizing ofa -relay ZCR through the normally closed switches of 1LS-1 and 5CR- 2.Contact 2CR1 of the relay 2CR is closed to Iform a holding circuitthrough V-8A whereas the Contact 2CR-2 energizes the clutch 118 of atimer 120, having a preset timer relay, to start fa timing cycle. Whenthe timer switches 2TR-2 and 2TR-3 are actuated, they energize a relaySCR and the solenoids 96 of the cutter causing descending of the knifeto cut web 28 in spaced 4relation to a trailing edge of a xero-graphicreproduction. As the cutter completes its downward stroke, .a portionthereof actuates microswitches 1LS-1 and ILS-2 thereby opening theirnormally closed contacts. Since ythe relay SCR and the solenoids .areenergized by timer 120, the normally closed contacts SCR-2 are opened asthe knife completes its downward stroke and the holding circuit of relayZCR is opened by ILS-1 to effect release. Opening of ZCR-Z deenergizesthe clutch 118 restoring timer 120 to its origi nal condition anddeenergizes relay SCR and the sole noids. As solenoids 96 Iaredeenergized, the knife is restored to its upper ineffective position asbefore. 'Ihe purpose for the timers 112 and 120 is to cause a delay inthe actuation of the cutter assembly 94 after detection by the detector82 order to permit movement of the web 28 to the position below theknife 90. The timing cycles for both timers are identical and are ofsuch a duration, based upon the speed of the web and the distance be.tween the detector and the knife, that cutting will occur substantiallyat the beginning and .terminal points of the pattern mark.

By the apparatus thus described there is disclosed appa4 ratus forforming electrostatic latent image control pat terns on a Xerographicdrum Vand apparatus to cut a continuous web in spaced relation to theleading and trailing edges of a xerographic reproduction printedthereon.

Since many changes could be made in the above construction and manyapparently Widely diiferent embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the drawings shall be interpreted as illustrative and notin a limiting sense. For instance, in the above description, theresultant control pattern is described as a continuous line having alength approximately equal to the length of the document beingreproduced. The relay 2CR-1 which serves to cause energization of thecorotron 64 may be Iactuated for a fraction of a second uponenergization of the relay 2CR. This will produce a single square-shapedpattern mark for each of the leading and trailing edges of the documentsbeing scanned.

What is claimed is:

A control dev-ice for use with a web cutting apparatus of an automaticxerographic printer having a Xerographic plate movable through a seriesof processing steps wlherein Ithe cutting apparatus is adapted to cut amoving web support surface in accordance with the leading and trailingedges of successive documents being Xerographically reproduced by theprinter, said control device including:

a control circuit having a scanning device adapted for detecting theleading and trailing edges of successive documents when lthe same arerespectively imaged upon the drum,

said circuit including means for producing .an electrical signal when aleading edge has been detected and a corotron positioned adjacent thedrum,

said corotron being adapted to produce a charge pattern on the drinn inresponse to said electrical signal whereby the charge pattern will bearranged along with images of the documents on the drum,

said charge pattern being adapted to produce -a control pattern on theweb support surface corresponding to each of the Xerog-raphicreproductions of the documents,

means for cutting the support surface,

detector means arranged in scanning relation to the web being adapted todetect the leading and trailing edges of said control pattern andproduce signals in accordance therewith, and

`an electric circuit connected to said cutting mean-s and having meansresponsive to said signal for actuating said cutting element whereby theweb support Inaterial is out at a point adjacent the leading andtrailing edge of the Xerographic reproductions of the documents.

References Cited by the Examiner UNITED STATES PATENTS 2,919,170 12/1959 lEpstein 95-1.7 X 2,919,672 1/1960 Benn et al. 95-1.7 X 3,013,89012/1961 Bixby 95-1.7 X 3,045,644 7/ 1962 SchWertz 95-1.7 X 3,105,425 10/1963 Cerasani 95-1.7

JOHN M. HORAN, Primary Examiner. EVON C. BLUNK, Examiner.

